Hmm... Well, as far as pregnancy issues, we hadn't really discussed them. However when I read your post, I brought up the questions to him. We're still thinking about if he gets other girls pregnant. However if I get pregnant, we've just come to conclusion that we would treat the child as his, no matter what.
We've talked a bit about dating. Both of us are in general more interested in finding people from our existing social interactions. We're both geeks and involved in conventions and other geek activities and would be meeting people through those circumstances. The guy that I've slept with is an old friend that lives in another state that came to visit for a week. Before he even came up to visit my fiance explicitly stated that he was okay with us having sex.
Either way, both of us has solidified that we want to know and get a chance to "feel out" a potential new partner the other is interested in. We've also stated that we'd like to know in advance if things seem to be heading in that direction with someone, so we have a chance to acclimate ourselves to the idea and figure out if we have an issue with a particular person (as I have already said no to the girl I mentioned before, as she seems to be just about collecting notches on her bedpost and has already been flagged as a potential crazy by several of our friends).
As far as his dating philosophy, it doesn't really affect me or mine, so much as mine affects him. I want to feel at ease with people I am sleeping with, and would prefer to be with people I already have a friendship with and that know my fiance and I as a couple. He isn't very comfortable with me sleeping with our closer social group (expanded social network is acceptable), and that presents a complication for me.
I suppose the one complication that his dating philosophy presents to me is that if he is pursuing girls that I haven't already had conversation with or know, then I'm not comfortable with it until I've gotten the chance to get a feel for them and know emotionally they aren't out to "get him".
Another part of the reason we're going to try and concentrate on already partnered people. Neither of us is looking for additional relationships. Any additional opposite gender partners are going to be at MOST friends with benefits. He would not necessarily be opposed to me finding a girlfriend, though I'm not looking for that as of right now.
I hope that answers your questions. :P